Device for washing hands

ABSTRACT

The present invention is in the field devices for hand washing, in particular the washing and drying of hands in public bathrooms. Accordingly it is an object of the present invention to provide a device for cleaning hands, especially a device for wetting hands, depositing a cleansing and/or disinfecting composition and rinsing consecutively, using a low amount of water. It has been found that an air-water jet nozzle assembly comprising two nozzles wherein a first nozzle is in fluid communication with a feed liquid source; and a second nozzle connected to a source of compressed air may be used to clean hands using low amounts of water in a short time.

FIELD OF THE INVENTION

The present invention is in the field devices for hand washing, inparticular the washing and drying of hands in public bathrooms.

BACKGROUND OF THE INVENTION

Washing hands is commonly perceived as hygienic and proven to be aneffective way to prevent spreading of several diseases.

Surveys show that people do not always wash their hands in publicbathrooms (also known as restrooms). Without wishing to be bound by atheory it is commonly perceived that public bathroom themselves are nothygienic and users prefer not to touch anything inside a public bathroomand wish to leave them at their earliest opportunity.

Over the years many things have been tried to make hand washing inpublic bathrooms more attractive.

For decades, electric dryers haven been used for drying hands afterwashing, to avoid dirty towels and paper towel dispensers that can runout of stock.

Soap dispensers have replaced soap bars and automatic taps have solvedthe problem of touching a dirty tap knob after washing to turn the wateroff.

U.S. Pat. No. 3,918,987 A (Kooper, Rudolph J.) discloses a hand andforearm cleaning device plurality of nozzles that eject streams offluids inwardly at predetermined rates and pressure in order to performwashing procedure. Though the device discloses an integrated solutionfor hand wash, it, however, do not address the issue of saving water andusing minimal amount for the operation.

All of these solutions are still highly cumbersome and time and spaceconsuming. Furthermore, although these developments have improved thecommon handwashing practice, an integrated solution for washing,disinfecting and drying hands that consumes less water remains to bedesired.

Accordingly it is an object of the present invention to provide adevice.

It is a further object to provide a device for wetting hands, depositinga cleansing and/or disinfecting composition and rinsing consecutively.

It is yet another object to provide a device that also dries the handsafter washing.

It is yet another object to use low amounts of water during washing.

Surprisingly it has been found that an air-water jet nozzle assemblycomprising two nozzles wherein a first nozzle is in fluid communicationwith a feed liquid source; and a second nozzle connected to a source ofcompressed air may be used to clean hands using low amounts of water ina short time.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a device for washing handscomprising a chamber comprising an opening for inserting at least onehand, at least one of an air-water jet nozzle assembly comprising twonozzles wherein a first nozzle is in fluid communication with a feedliquid source; and a second nozzle connected to a source of compressedair.

In another aspect the invention provides a process for cleansing a handwith an air-water jet nozzle assembly comprising two nozzles wherein afirst nozzle is in fluid communication with a feed liquid source; and asecond nozzle connected to a source of compressed air; and comprisingthe steps of: spraying a fine mist of detergent composition onto thehand; rinsing the hand by spraying a fine mist of water onto it; anddrying the hand by blowing air onto the hand.

These and other aspects, features and advantages will become apparent tothose of ordinary skill in the art from a reading of the followingdetailed description and the appended claims. For the avoidance ofdoubt, any feature of one aspect of the present invention may beutilised in any other aspect of the invention. The word “comprising” isintended to mean “including” but not necessarily “consisting of” or“composed of.” In other words, the listed steps or options need not beexhaustive. It is noted that the examples given in the description beloware intended to clarify the invention and are not intended to limit theinvention to those examples per se. Similarly, all percentages areweight/weight percentages unless otherwise indicated. Except in theoperating and comparative examples, or where otherwise explicitlyindicated, all numbers in this description indicating amounts ofmaterial or conditions of reaction, physical properties of materialsand/or use are to be understood as modified by the word “about”.Numerical ranges expressed in the format “from x to y” are understood toinclude x and y. When for a specific feature multiple preferred rangesare described in the format “from x to y”, it is understood that allranges combining the different endpoints are also contemplated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic drawing of the air-water jet nozzles

FIG. 2 shows drawings of the air-water jet nozzles.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a device for hand washing. The deviceaccording to the invention may further be suitable for drying hands. Thedevice is particularly suitable for use in public bathrooms, such asairport bathrooms, gas station bathrooms, office bathrooms, hospitalbathrooms, etc. In home application of the device is also envisaged.

The device according to the invention comprises a chamber comprising anopening for inserting at least one hand, and an air-water jet nozzleassembly comprising two nozzles wherein a first nozzle is in fluidcommunication with a feed liquid source; and a second nozzle connectedto a source of compressed air.

Chamber

The chamber comprises an opening for inserting a hand for washing withthe device. The chamber may optionally comprise more than one openingfor inserting two or more hands simultaneously, or a larger opening forthe same purpose.

The opening may be at any end of the chamber. The most suitable sidesfor an opening is either at the top, for vertical insertion of thehands, or at one of the sides for horizontal insertion, or anywhere inbetween. An opening for the insertion of hands at the bottom, is notexcluded from the scope of this application, but is typically notpreferred by the intended user.

The chamber further comprises an air-water jet nozzle assemblycomprising two nozzles, one for air and one for a liquid. Preferably thechamber may comprise more than one air-water jet assembly, even morepreferably the device contains an array of air-water jet nozzles thatsimultaneously cover the whole surface of the hand, at least one side atthe time, but preferably on both sides.

Air-Water Jet Assembly

The air-water jet assembly comprises two nozzles wherein a first nozzleis in fluid communication with a feed liquid source; and a second nozzleconnected to a source of compressed air. The air-water jet device isincorporated into a hand washing device.

The liquid source may be any water source, either provided to theair-water jet device straight from the water mains, through a pump,through a pressured container holding the water or by any other means,or even by gravity (i.e. by placing the water reservoir above the heightof use of the air-water jet.

The feed liquid may be any liquid. For regular skin cleansing an aqueouscomposition is typically preferred. The nozzle for the liquid is calledwater nozzle herein below, but it is understood that the water nozzlemay pass water or any other liquid, including aqueous liquids and otherskin treatment composition optionally comprising benefit agents.

Similarly, the air source may be any air source, either provided througha compressor, separate from, or built into the hand washing device, orthrough a compressed air line, such as often available in hospitals.

It is preferred that the air may be heated. It is preferred that the airtemperature is at least 30° C., more preferably at least 35° C., stillmore preferably at least 40° C., but typically less than 70° C., morepreferably less than 65° C., or even less than 60° C.

Both, the first nozzle, (water nozzle) and the second nozzle (airnozzle) are positioned relative to an imaginary central axis (NOR). Thefirst nozzle is positioned at an angle (a) of between 1 and 60°,preferably between 10° and 30° relative to the central axis; and thesecond nozzle is at an angle (φ) of between 1 and 45°, preferablybetween 15° and 30° relative to the central axis.

The mouth of the second nozzle is positioned more forward in thedirection of the flow along the direction of the central axis than themouth of the first nozzle, wherein the offset (OS) distance between themouth of the first nozzle and the second nozzle is between 0.5 and 5 mmin said direction, preferably 1-3 mm.

The best results are obtained when the first nozzle has an opening ofbetween 0.05 and 10 mm², preferably even at least 0.2 mm², and not morethan 7 mm², more preferably not more than 5 mm² or even less than and 3mm². Similarly, the opening of the second nozzle is preferably between0.2 and 3 mm².

For nozzles with a circular opening, the diameter of the first nozzle ispreferably between 0.25 and 3.5 mm, preferably at least 0.5 mm, butpreferably not more than 3 mm, more preferably not more than 2.5 mm, oreven less than 3 mm; while the diameter of the second nozzle ispreferably between 0.5 and 2 mm.

The scope of the present invention further includes configurationscomprising two or more water nozzles directed at a single air nozzle.Although this adds to the complexity of the device, which is generallynot preferred, it provides the additional benefit of point of actionmixing or reacting different or incompatible ingredients. Additionallydifferent nozzle geometries are contemplated, including but not limitedto circular, square, rectangular and oval openings, for either one orboth nozzles. For larger surfaces, a slit type (oval or rectangular) airnozzle and a similarly dimensioned water nozzle, or multiple waternozzles are preferred, more preferably the ratio between the longestside-to-side distance and the shortest side-to-side distance of the ovalor rectangular slit, is between 2:1 and 20:1, still more preferablybetween 2:1 and 10:1. Cross or star shaped air nozzles with one or morewater nozzles being positioned between the extending parts (i.e. in theindentations) are also contemplated in this context.

Without wishing to be bound by a theory, it is thought that the presentinvention derives its performance from the positioning of the nozzlesrelative to the imaginary axis and the offset of the water nozzle (firstnozzle) relative to the air nozzle (second nozzle). Because of thispositioning, the feed liquid coming from the water nozzle forms a filmaround the air nozzle, and because of this, it gives a finer spray at alower liquid-to-air ratio (i.e. using less liquid). The air flow fromthe air nozzle is thought to create a local under-pressure that ensuresthat the liquid is driven in the direction of the air nozzle along theair nozzle tip, regardless of in which direction the nozzle is pointed.Furthermore, the liquid flow is not affected by the air pressure due tothe separation of the air and water nozzle openings, which is a commonproblem with internal mix nozzle designs.

It is preferred that the distance of the hands from the nozzles is atleast 1 cm and at most 15 cm The distance is preferably at least 2 cm,more preferably at least 3 cm, or even at least 4 cm. The distance ispreferably not more than 12 cm, more preferably not more than 10 cm, oreven not more than 8 cm.

It is preferred that the liquid:air ratio is between 10:90 and 1:9999,more preferably less than 5:95, still more preferably less than 4:96,even more preferably less than 3:97, less than 2:98 or even less than1:99, while the ratio is preferably higher than 3:9997, more preferablyhigher than 5:9995.

It is further preferred that there is only a short distance between theopening of the water nozzle and the side of the air nozzle, thisdistance is preferably less than 2 mm, more preferably less than 1 mm,or even less than 0.5 mm. It is most preferred that the opening of thewater nozzle is touching the air nozzle.

It is preferred that the air nozzle does not co-axially surround thewater passage. It is also preferred that the water nozzle does notco-axially surround the air nozzle.

The air pressure of the air source is preferably in the range of 1 to 5bar. The air preferably has a velocity of greater than 80 m/s at theexit of the nozzle (the nozzle opening), preferably greater than 120m/s, more preferably greater than 180 m/s, and most preferably greaterthan 250 m/s. Although the invention would work up to very high airvelocities, it is preferred for constructional reasons and conveniencefor the user, that the air velocity is less than the speed of sound(i.e. less than 334 m/s). Depending on the nozzle diameter, the airflowrate is preferably between 3 and 50 l/min, preferably more than 5 l/minor even more than 10 l/min. The air flow rate is preferably less than 40l/min, more preferably less than 30 l/min or even less than 25 l/min.

The liquid flow rate is typically between 2 and 100 ml/min, preferablymore than 5 ml/min or even more than 10 ml/min, while the liquid flowrate is preferably less than 80 ml/min, more preferably less than 50ml/min, or even less than 40 ml/min.

Configuration

The air and/or liquid sources may be incorporated into the device, or befitted in a separate unit. In the latter case, a separate unitcomprising a compressor, a compressed air cartridge or cylinder, oranother source of air and/or a liquid reservoir, optionally connected tothe water mains, is provided. The unit is connected to a hand helddevice by means of a tubing as air line and/or water line.

A device that is fully integrated with the air, water and drain plumbingis preferred for public bathrooms, while in home, the water may be addedand the drain may be emptied manually.

Nozzle Array

The device comprises at least one nozzle assembly, comprising an airnozzle and a water nozzle.

It is preferred that the device comprises several nozzles per hand,preferably between 1 and 25 per hand. However, for the purpose of easypositioning and operation between 1 and 12 nozzles per hand is found togive the best results. The nozzles may be configured such that theyspray one side of the hand only, or both sides simultaneously. Thenozzle assemblies may be configured as a row along a linear profile, orin a curved manner, e.g. a curve following the shape of an average hand.Typically a row of nozzles comprises between 1 and 6 nozzle assemblies,preferably between 2 and 4 assemblies. It is also contemplated in thecontext of the present invention to have more than one row of nozzleassemblies per side of the hand.

The device of the present invention may further incorporate othercleaning features such as bristles, scrubbers and/or massaging elements,but from a hygiene perspective this is not preferred.

An array with air-water jet nozzles may be mounted on a movable rig,such that the mist spray may be moved over a larger area instead ofusing more nozzles.

The device may further comprise an air compressor as air source. Thecompressor may be built into chamber of the device, or provided as aseparate device that is connected to the air-water jet by means of atube. The compressor preferably provides at least 1 bar pressure and notmore than 5 bar, preferably less than 4 bar. Thus, very low powercompressors, typically in the range of 0.05 to 1 HP, can be used toachieve the above specifications. Due to a pressure drop in the tubingand the device, the pressure at the air nozzle will preferably be in therange of 1 to 4 bar, more preferably 2 to 3 bar. A device with a meansto set the pressure is also contemplated; in this case the user is, forinstance, able to choose between skin surface cleansing, or deep porecleansing.

The liquid source may be the water mains, i.e. directly connected to thefaucet, or be in the form of a separate reservoir. The pressure on theliquid source for use with the cleaning device may be relatively low,preferably at least 0.05 bar, more preferably at least 0.1 bar, butpreferably not more than 3 bar, more preferably less than 2.5 bar, stillmore preferably less than 2 bar.

When a separate reservoir is used as liquid source, said reservoir maybe filled with water only, a cleaning composition, a compositioncomprising benefit agents.

The liquid reservoir may be placed above the level of use of thecleaning device, such as to provide pressure, or may be pressuredseparately. When pressured separately, it is especially preferred thatthe reservoir is pressurised with compressed air from the compressed airsource.

Drying

The device according to the invention may further provide thepossibility to dry the hands after cleaning/treating.

This may be done by blowing only air, preferably heated air, through theair nozzles; and stop the water flow to the water nozzles. Alternativelya separate array of nozzles for the drying into the same washing anddrying chamber is also contemplated.

It is preferred that the air velocity is at least 10 m/s, morepreferably at least 20 m/s, still more preferably at least 30 m/s, whilethe air velocity is typically less than 200 m/s, more preferably lessthan 150 m/s, or even less than 100 m/s.

It is preferred that the airflow is at least 10 L/s, preferably at least20 L/s, still more preferably at least 30 L/s, or even at least 50 L/s,while the flow is typically less than 1000 L/s, or more preferably lessthan 800 L/s, still more preferably less than 500 Us, still morepreferably less than 300 L/s, or even less than 100 L/s.

It is preferred that the temperature of the air for drying in s at least30° C. more preferably at least 40° C., or even more than 50°, buttypically less than 100° C., more preferably less than 90° C., stillmore preferably less than 80°, or even less than 70° C.

The air may be blown from any direction, but preferably from the top tothe bottom.

Treatment Compositions

Different kinds of treatment compositions are envisaged within the scopeof this invention.

The device according to the invention may apply to the skin various skincare and cleansing products, including but not limited to hand soap,hand hygiene and fragrance compositions.

It is preferred that the contact time of the product with the skinbefore rinsing is at least 5 seconds, more preferably at least 10seconds, still more preferably at least 15 seconds, or even at least 20seconds.

It is preferred that the hand cleaning method according to theinvention, is capable of cleaning a hand in less than 1 minute,preferably less than 45 seconds, or even less than 30 seconds.

The pH of the compositions is preferably neutral or mildly acidic, morepreferably between pH 2 and 9, still more preferably at least pH 3,while more preferably less than pH 8, still more preferably less than pH7, or even less than pH 6.

Hand Cleansing

Hand cleansing compositions and/or sanitisation products typicallycomprise surfactants, preferably anionic surfactants, such as SLS andSLES, soluble soaps and/or non-ionic surfactants such as alcoholethoxylates. The concentration of the surfactants is typically 0.2-5g/L, preferably 1-3 g/L.

Hand Sanitisation

The device is also suitable for spraying a hand sanitisation agent ontothe hand. The sanitisation agent may be incorporated in the cleansingcomposition, or may be applied instead of washing, or after washing.Common sanitisation agents include lower alcohols and quaternaryammonium biocides, as commonly understood by the skilled person.

Operation

While using the device, the air-water jet may be used continuously, ordiscontinuously. One way of operation that is considered is to use theair-water jet during part of the operation. In another embodiment, theair-water jet is used in the first part of the cleaning process forcleaning and run with only the liquid flow or the liquid flow and lowair flow to deposit a benefit agent to the hand, such as a hand cream orlotion.

In another embodiment the air-water jet is operated in a pulsed modei.e. the air flow is controlled in an on-off fashion over time. In yetanother embodiment the handheld device is fitted with a push button toswitch the air-water jet on or off while cleansing and treatment skin(also including hair, scalp and other keratinous surfaces are definedherein above).

In any of the discontinuous operations, it is preferred to open and shutthe air and/or liquid lines with a suitable solenoid valve.

A valve system may also be used to open the liquid and/or air lines whenthe device is in operation, while shutting the liquid and/or air lineswhen the device is not in use.

The invention will now be illustrated with reference to the followingnon-limiting figures and examples. The embodiments and examples are byway of illustration only and do not limit the scope of invention in anymanner.

Accordingly, the invention provides a process for cleansing a hand withan air-water jet nozzle assembly comprising two nozzles wherein a firstnozzle is in fluid communication with a feed liquid source; and a secondnozzle connected to a source of compressed air; and comprising the stepsof spraying a fine mist of detergent composition onto the hand, rinsingthe hand by spraying a fine mist of water onto it, drying the hand byblowing air onto the hand.

Preferably, the process is preceded by the step of spraying a fine mistof water onto the hand for wetting.

The most preferred temperature of the air for reasons of skin comfort is30°-70° C.

The ratio of air to water from the nozzle assembly is typically between90:10 and 99.9:0.1

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a configuration wherein, the nozzle (N) has the outlet portfor liquid (OPW) positioned away from the substrate relative to theoutlet port for air (OPA), offset by a distance (OS). The angle ofincidence of the outlet port for liquid with respect to the substrate(FS) is defined by the angle. The angle of incidence of the outlet portfor air with respect to the substrate (FS) is defined by the angle. Thedashed line NOR represents an imaginary line which is normal to thesurface of the substrate. As is apparent, in this embodiment of thenozzle the angle is greater than the angle. The air exits from thenozzle through outlet port for air (OPA) and the liquid exits throughthe outlet port for liquid (OPW).

FIG. 2 shows a configuration with 1 air nozzle and 1 water nozzle.

EXAMPLES

The invention will now be demonstrated by means of the followingnon-limiting examples.

Example 1 Hand Cleansing

In this example the cleansing of hands by means of the device accordingto the present invention is compared to regular hand cleansing with thesame cleaning formulation.

Pre-Treatment

Prior to the test, the hands of the example and the comparative examplewere decontaminated with 70% alcohol to remove the normal flora from thehands, and were allowed to dry and were washed with sterile distilledwater to remove traces of alcohol.

Then 100 microlitres containing of 10⁷ cells of non pathogenic strain ofE.coli (in the 100 microlitre) was applied onto each hand and thevolunteers were asked to spread the culture across the palms andfingers.

One hand (example 1) was washed with 10 ml of 3 g/L of an ethoxylatedalcohol non-ionic surfactant (C_(<12>)EO_(<7>), non-ionic surfactant)for 15 seconds and the other hand (Comparative example A) was washedwith the same amount of the same surfactant using the air-water jetdevice according to the invention for 15 seconds.

The air-water jet in the example comprised two nozzle assemblies; andthe air pressure for the air-water jet device was 4 bar with a liquidflow rate of 20 ml/min per nozzle assembly.

The handwashing according to the invention was carried out in anair-tight chamber for safety purposes.

The remaining bacteria on the hands were measure in a conventionalmethod.

Results

The washing results in terms of residual colonies (expressed asCFU/hand) are given in the table below.

Results

Example 1 Comp A Applied log CFU/hand 7 7 Residual log CFU/hand 4.2 3.6

It becomes clear from table above that the washing process with theair-water jet device removes about 0.6 log more of the E.coli than theconventional washing method.

1. A device for washing hands comprising a chamber comprising: i) Anopening for inserting at least one hand; ii) At least one of a air-waterjet nozzle assembly, characterized by comprising two nozzles wherein afirst nozzle (PW) is in fluid communication with a feed liquid source;and a second nozzle (PA) connected to a source of compressed air;wherein, the first nozzle is at an angle (α) of between 1 and 60°relative to the central axis; and the second nozzle is at an angle (φ)of between 1 and 45° relative to the central axis (NOR); and wherein theair nozzle does not co-axially surround the water passage; and whereinthe mouth of the second nozzle (OPA) is positioned more forward in thedirection of the flow along the direction of the central axis than themouth of the first nozzle (OPW), wherein the offset distance (OS)between the mouth of the first nozzle and the second nozzle is between0.5 and 5 mm in said direction.
 2. A device according to claim 1,wherein: a) the mouth of the first nozzle of the device has an openingof 0.2-3.5 mm²; b) the mouth of the first nozzle of the device is lessthan 1 mm away from the wall of the second nozzle.
 3. A device accordingto claim 1, wherein the device is connected to a separate unitcomprising a compressor and a reservoir for holding the liquid, thecompressor being the source of the compressed air and the reservoirholding the liquid being the liquid source.
 4. A process for cleansing ahand with an air-water jet nozzle assembly comprising two nozzleswherein a first nozzle is in fluid communication with a feed liquidsource; and a second nozzle connected to a source of compressedcharacterized in that the first nozzle is at an angle (α) of between 1and 60° relative to the central axis; and the second nozzle is at anangle (φ) of between 1 and 45° relative to the central axis (NOR); andwherein the air nozzle does not co-axially surround the water passage;and wherein the mouth of the second nozzle (OPA) is positioned moreforward in the direction of the flow along the direction of the centralaxis than the mouth of the first nozzle (OPW), wherein the offsetdistance (OS) between the mouth of the first nozzle and the secondnozzle is between 0.5 and 5 mm in said direction; and comprising thesteps of: a) Spraying a fine mist of detergent composition onto thehand; b) Rinsing the hand by spraying a fine mist of water onto it; c)Drying the hand by blowing air onto the hand.
 5. A process according toclaim 4, wherein said process is preceded by the step of spraying a finemist of water onto the hand for wetting.
 6. A process according to claim4, wherein the air is heated to 30°-70° C.,
 7. A process according toclaim 4, wherein the ratio of air to water from the nozzle assembly isbetween 90:10 and 99.9:0.1.